1. Ultrasonic, Infrasonic and audible waves travel
through a medium with speeds \[V_{u},V_{i}\] and \[V_{a}\]
respectively, then
a) \[V_{u},V_{i}\] and \[V_{a}\] are nearly equal
b) \[V_{u}\geq V_{a} \geq V_{i}\]
c) \[V_{u}\leq V_{a} \leq V_{i}\]
d) \[V_{a}\leq V_{u}\] and \[V_{u}\approx V_{i}\]
Explanation: \[V_{u},V_{i}\] and \[V_{a}\] are nearly equal
2. The distance between two consecutive crests in a
wave train produced in a string is 5 cm. If 2
complete waves pass through any point per
second, the velocity of the wave is
a) 10 cm/sec
b) 2.5 cm/sec
c) 5 cm/sec
d) 15 cm/sec
Explanation:
3.A tuning fork makes 256 vibrations per second in
air. When the velocity of sound is 330 m/s, then
wavelength of the tone emitted is
a) 0.56 m
b) 0.89 m
c) 1.11 m
d) 1.29 m
Explanation:
4. A man sets his watch by a whistle that is 2 km
away. How much will his watch be in error.
(speed of sound in air 330 m/sec)
a) 3 seconds fast
b) 3 seconds slow
c) 6 seconds fast
d) 6 seconds slow
Explanation:
5. When a sound wave of frequency 300 Hz passes
through a medium the maximum displacement of
a particle of the medium is 0.1 cm. The maximum
velocity of the particle is equal to
a) \[60 \pi\] cm/sec
b) \[30 \pi\] cm/sec
c) 30 cm/sec
d) 60 cm/sec
Explanation:
6. Sound waves have the following frequencies that
are audible to human beings
a) 5 c/s
b) 27000 c/s
c) 5000 c/s
d) 50,000 c/s
Explanation: Audiable range of frequency is 20Hz to 20kHz
7. Velocity of sound waves in air is 330 m/sec. For a
particular sound in air, a path difference of 40 cm
is equivalent to a phase difference of \[1.6\pi\] . The
frequency of this wave is
a) 165 Hz
b) 150 Hz
c) 660 Hz
d) 330 Hz
Explanation:
8. The wavelength of ultrasonic waves in air is of
the order of
a) \[5\times 10^{-5}cm\]
b) \[5\times 10^{-8}cm\]
c) \[5\times 10^{5}cm\]
d) \[5\times 10^{8}cm\]
Explanation:
9.The relation between phase difference \[\left(\triangle \phi\right)\] and
path difference \[\left(\triangle x\right)\] is
a) \[\triangle \phi=\frac{2\pi}{\lambda}\triangle x\]
b) \[\triangle \phi=2\pi \lambda\triangle x\]
c) \[\triangle \phi=\frac{2\pi\lambda}{\triangle x}\]
d) \[\triangle \phi=\frac{2\triangle x}{\lambda}\]
Explanation: \[\triangle \phi=\frac{2\pi}{\lambda}\triangle x\]
10. A hospital uses an ultrasonic scanner to locate
tumours in a tissue. The operating frequency of
the scanner is 4.2 MHz. The speed of sound in a
tissue is 1.7 km- \[s^{-1}\] lambda. The wavelength of sound in
the tissue is close to
a) \[4\times 10^{-4} m\]
b) \[8\times 10^{-3} m\]
c) \[4\times 10^{-3} m\]
d) \[8\times 10^{-4} m\]
Explanation:
